1,3-Oxazole-4-carbonyl chloride → N-[6-(3-{[3-(1-cyano-1-methylethyl)benzoyl]amino}-4-methylphenoxy)-1,3-benzothiazol-2-yl]-1,3-oxazole-4-carboxamide

1,3-Oxazole-4-carbonyl chloride synthesized above was suspended in pyridine (4.0 mL) at 0° C., N-{5-[(2-amino-1,3-benzothiazol-6-yl)oxy]-2-methylphenyl}-3-(1-cyano-1-methylethyl)benzamide (200 mg, 0.452 mmol) produced in Example A7(vi) was added, and the mixture was stirred at room temperature for 12 hr. The reaction mixture was concentrated under reduced pressure, and the residue was suspended in methanol (4.0 mL). 1N Aqueous sodium hydroxide solution (4.0 mL) was added, and the mixture was stirred at room temperature for 30 min. To the reaction mixture was added 1N hydrochloric acid (10 mL), and the mixture was extracted with ethyl acetate (100 mL). The organic layer was washed with 5% aqueous sodium hydrogencarbonate solution (50 mL) and saturated brine (50 mL), successively, and dried over anhydrous sodium sulfate. The insoluble material was filtered off, and the filtrate was concentrated under reduced pressure. The obtained residue was purified by basic silica gel column chromatography (hexane/ethyl acetate=70/30→0/100), and the obtained solution was concentrated under reduced pressure. The residue was triturated with ethyl acetate/diisopropyl ether to give the title compound (70 mg, 29%) as a colorless solid.